CloudFormation template with VPC, public and private subnets, prepared for deployment of a database and an API. Article with explanation available here: http://rozchmurzeni.pl/vpc---prywatne-podsieci

first.yaml

AWSTemplateFormatVersion: 2010-09-09
Description: >-
    VPC with private subnet prepared for deployment of DB and API.
    Full article with explanation available here: http://rozchmurzeni.pl/vpc---prywatne-podsieci
Resources:
    Vpc:
        Type: AWS::EC2::VPC
        Properties:
            CidrBlock: 10.0.0.0/16
            EnableDnsHostnames: true
    InternetGateway:
        Type: AWS::EC2::InternetGateway
    InternetGatewayAttachment:
        Type: AWS::EC2::VPCGatewayAttachment
        Properties:
            InternetGatewayId: !Ref InternetGateway
            VpcId: !Ref Vpc
# Publiczny subnet
    PublicRouteTable:
        Type: AWS::EC2::RouteTable
        Properties:
            VpcId: !Ref Vpc
    InternetRoute:
        Type: AWS::EC2::Route
        Properties:
            DestinationCidrBlock: 0.0.0.0/0
            RouteTableId: !Ref PublicRouteTable
            GatewayId: !Ref InternetGateway
    PublicSubnet:
        Type: AWS::EC2::Subnet
        Properties:
            AvailabilityZone: eu-west-1a
            CidrBlock: 10.0.1.0/24
            MapPublicIpOnLaunch: true
            VpcId: !Ref Vpc
    PublicSubnetTableAssociation:
        Type: AWS::EC2::SubnetRouteTableAssociation
        Properties:
            RouteTableId: !Ref PublicRouteTable
            SubnetId: !Ref PublicSubnet
# Prywatny subnet
    PrivateRouteTable:
        Type: AWS::EC2::RouteTable
        Properties:
            VpcId: !Ref Vpc
    PrivateSubnet:
        Type: AWS::EC2::Subnet
        Properties:
            AvailabilityZone: eu-west-1c
            CidrBlock: 10.0.3.0/24
            VpcId: !Ref Vpc
    PrivateSubnetTableAssociation:
        Type: AWS::EC2::SubnetRouteTableAssociation
        Properties:
            RouteTableId: !Ref PrivateRouteTable
            SubnetId: !Ref PrivateSubnet
# Security grupy
    ApiSecurityGroup:
        Type: AWS::EC2::SecurityGroup
        Properties:
            GroupDescription: Api security group
            GroupName: api-security-group
            SecurityGroupIngress:
                -   Description: Open https traffic
                    CidrIp: 0.0.0.0/0
                    IpProtocol: TCP
                    FromPort: 443
                    ToPort: 443
            VpcId: !Ref Vpc
    DatabaseSecurityGroup:
        Type: AWS::EC2::SecurityGroup
        Properties:
            GroupDescription: Database secruity group
            GroupName: db-security-group
            SecurityGroupIngress:
                -   Description: Allow traffic from api
                    IpProtocol: TCP
                    FromPort: 3306
                    ToPort: 3306
                    SourceSecurityGroupId: !Ref ApiSecurityGroup
            VpcId: !Ref Vpc